Abstract

The anisotropic resistivities (AR) in La0.67Ca0.33MnO3filmsgrown on orthorhombic NdGaO3(100) substrates were investigated. In this epitaxial system, the large anisotropic misfit strain was demonstrated to induce an antiferromagnetic insulator (AFI) phase transition near ∼250 K, leading to phase separation (PS) with the coexistence of AFI and ferromagnetic-metal (FM) phases at the temperature below. In the PS regime, the resistivity measured along the highly strained b-axis is greater than that along c-axis, giving rise to a huge AR. It can reach ∼12 500% and shows strong dependence on the amplitude and orientation of the magnetic field. We ascribed this unusual AR to the anisotropic-strain-controlled MnO6 octahedral deformations which can organize the competing AFI and FM phases into orientation-preferred PS pattern, thus resulting in the anisotropic percolative transport.

Key Topics

[Magnets or magnetic bodies characterised by the
magnetic materials therefor; Selection of materials for their magnetic
properties, Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties]